1. Field of the Invention
This invention relates generally to the field of photovoltaic systems. More particularly, this invention relates to concentrated solar photovoltaic systems and parts thereof.
2. State of the Art
Terrestrial solar photovoltaic systems convert solar insolation into electrical energy using photovoltaic cells. The amount of electrical energy that a photovoltaic cell produces is proportional to the intensity of the insolation it receives and the surface area of the cell. Photovoltaic cells are typically made from various semiconductor materials such as, but not limited to, silicon or gallium arsenide. Single junction photovoltaic cells, which are typically realized by silicon material, are less efficient at converting solar isolation to electrical energy, and thus require a larger size and a greater number of cells to provide a required amount of electrical output. Multiple junction (MJC) photovoltaic cells, which are typically realized by gallium arsenide material, by contrast, are more efficient, and require less size and a smaller number of cells to provide a required amount electrical output.
Concentrating the insolation received by a photovoltaic cell can effectively decrease costs by increasing the electrical output of the photovoltaic cell. One form of concentration is realized by a concentrator lens and a light guide that cooperate to channel insolation to the photovoltaic cell. These components must be manufactured and assembled with tight tolerances in order to properly channel sunlight to the photovoltaic cell. In addition, the photovoltaic cell heats up as it receives insolation. This heat limits the photovoltaic cell's efficiency. A number of housings and mounting devices have been disclosed in the art that support photovoltaic cells and associated concentration mechanisms. Among these are U.S. Pat. No. 6,399,874; PCT Pub. No. WO 2006/114457 A1; and U.S. Pat. No. 6,483,093. These photovoltaic cell systems presently rely on an adhesive bond between the light guide and the photovoltaic cell to mechanically support the secondary optical device in place above the photovoltaic cell. The adhesive bond thus takes on a mechanical load due to the weight of the light guide and the lateral and/or sheering forces that arise from the transportation, positioning, or movement of the system.